John Wanamaker, one of the pioneers in advertising and marketing in the United States, once commented with no small amount of tongue in his cheek: “Half the money I spend on advertising is wasted; the trouble is I don’t know which half.” Below is a guest post by Aubree Parsons , a bright and energetic writer/journalist focused on many topics including marketing. When billboards and television commercials were the main sources of advertising , it was impossible to tell how influential each individual ad was on consumers – which produced the results, and which were totally wasted.